From the viewpoint of processing of cheese, it is advantageous to impart certain properties for resisting heat treatment at a temperature higher than several tens degree centigrade, such as shape retention of the cheese. Then, various techniques have heretofore been proposed to provide heat resisting shape retention properties to cheese. For Example, addition of a specific viscosity modifier or protein such as albumin has been proposed [for Example, Japanese Patent Publication Nos. 49-37266 (WPI C74-V76761) and 58-46311 (WPI C79-B12945), Japanese Patent Laid Open Publication No. 55-11292 and 59-198938 (WPI C84-134865)]. Japanese Patent Publication No. 58-56608 (WPI C77-Y64154) and Japanese Patent Laid Open Publication No. 61-1358 (WPI C86-019695) disclose the use of alginic acid or an alginate to improve slightly melt properties with heating. However, shape retention against microwave irradiation heating can not be improved unless a large amount of an alginate is used, whereas the use of too much alginate causes problems. For Example, cheese obtained has inferior mouthfeel such as jelly-like mouthfeel and, when a dehydrated product is prepared therefrom and it is reconstituted with hot water, a hard non-reconstituted part remains.
On the other hand, microwave ovens have become more frequently used for cooking food. However, since as microwave heating causes vaporization of water from inside of food, the above techniques for providing heat resistance can hardly impart shape retention to cheese. Moreover, in an extreme case, the cheese itself is separated into oil and protein and other components and is broken up.
Further, in general, it is difficult to use cheese as an ingredient of instant foods and the like because, when cheese in a shaped state such as blocks or granules is dried or dehydrated as it is, the resulting dehydrated product is hardly reconstituted with hot water. Japanese Patent Laid Open Publication No. 61-158746 (Patent Abstracts of Japan, Vol. 10, No. 362 (C-389) [2419], Dec. 4, 1986) and Japanese Patent Application No. 61-314643 (co-pending U.S. patent application Ser. No. 136,635) have proposed processes for producing dehydrated cheese to solve this problem. These processes for producing dehydrated cheese are useful for obtaining a dehydrated product which can be completely reconstituted with hot water without any hard non-reconstituted part remaining. And, the product can show certain shape retention properties upon reconstitution. However, particularly, in the case of reconstitution with water by using internal heating means such as microwave irradiation, there is still a drawback that it is impossible to prevent separation and loss of cheese. According to the present inventors' finding, even if a conventional technique is simply employed in the latter processes for producing dehydrated cheese to impart the above shape retention properties against heat to cheese, no significant effect can be obtained or, rather, mouthfeel of the product is impaired.
As a result of the present inventors' intensive studies, it has been found that a certain cellulose ether possesses resistance to microwave heating, and further that, in the case of using a cellulose ether having a specific viscosity with or without a water-soluble alginate and a calcium salt, the desired result can be obtained merely by using a small amount of the cellulose ether.